According to a press release from the University of Tokyo, galaxy GN-z11 may be the most distant galaxy ever discovered. They believe by deduction, it may be the most distant galaxy overall.
“From previous studies, the galaxy GN-z11 seems to be the farthest detectable galaxy from us, at 13.4 billion light years, or 134 nonillion kilometers (that’s 134 followed by 30 zeros),” said Professor Nobunari Kashikawa from the Department of Astronomy at the University of Tokyo. “But measuring and verifying such a distance is not an easy task.”
"The so-called redshift in GN-z11 was calculated by Kashikawa with his team. This corresponds to how light expands and gets redder, the more distant it goes. Some molecules, called emission lines, imprint various light patterns from far-off objects. By calculating how far these telltale signatures are extended using a tool called MOSFIRE, astronomers can understand how far the light has to journey away from the target galaxy.
The MOSFIRE collected in depth the GN-z11 emission lines, allowing the team to approximate its distance much better than was possible with previous results. It is not wise to use our known kilometers units, or even multiples of them, when dealing with distances at certain scales. Rather, astronomers are using the so called redshift count denoted by z. The accuracy of the z galaxy value was increased by 100, with his team, Kashikawa. When future measurements can prove this, scientists can conclude that GN-z11 is the farthest galaxy in the universe ever.
“We looked at ultraviolet light specifically, as that is the area of the electromagnetic spectrum we expected to find the redshifted chemical signatures,” said Kashikawa. “The Hubble Space Telescope detected the signature multiple times in the spectrum of GN-z11. However, even the Hubble cannot resolve ultraviolet emission lines to the degree we needed. So we turned to a more up-to-date ground-based spectrograph, an instrument to measure emission lines, called MOSFIRE, which is mounted to the Keck I telescope in Hawaii.”